1. Field of the Invention
The present invention concerns a method for producing a disk of pizza dough ready to be topped and baked, and an apparatus for implementing the method.
2. Discussion of Background Information
In manually processing pizza dough, for which a leavened dough is used for obtaining the softness desired, it is known that the pizzaiolo (pizza baker) starts with a ball of kneaded dough which he flattens pressing it lightly between his hands in order to get a rather thick disk of a thickness of the order of centimeters and of a diameter much smaller than the desired final diameter and then applying skillful manipulations beating the dough, and above all twirling it in the air, expands the disk to the final diameter. In this operation the centrifugal force plays a fundamental role as the enlargement of the disk is effected to a large extent under the influence of this force generated by the rotation of the disk about a virtual rotational axis. This traditional manner of processing the pizza dough renders the dough excellently thin and soft in such a manner that, after baking, optimum characteristics of the finished product required by the market are ensured. The manual method of producing pizza dough thus is ideal and practically cannot be further improved. The manual method, however, presents a basic disadvantage insofar as a degree of manual skill is required of the pizzaiolo which very rarely is found and thus one is compelled to put up with insufficiently trained pizza bakers, and the poor quality results can easily be imagined.
Moreover, the process of manually expanding the dough, certainly spectacular as such, is time consuming and thus the hourly production of a pizzaiolo (pizza baker) is limited which results in an elevated price for the finished product.
For these reasons, in practical use and in the patent literature numerous proposals have become known for replacing the manual processing method of the pizzaiolo by a mechanized production of the pizza dough. These proposals can be grouped into two distinct categories. In one category, there are the (numerous) proposals based on the general idea of pressing the dough into a mold squeezing it from the inner area towards the outer area. It is to be stated right away that a system of this type cannot yield good results, even if such devices have been realized, and thus for this reason a further description can be dispensed with. Actually, subjecting the dough to high pressure implies that all the small air bubbles formed in the dough during the leavening process are eliminated. Leavening actually just is aimed at softening the dough composed of water, flour and salt, which otherwise would remain compact, by favoring the formation of small air bubbles in it. Evidently extending systems in which the leavened dough is compressed strongly also compress the micro cavities therein and squeezes the air out of the dough. From an operation of this type, a compacted dough results which is not pleasant tasting when eaten, and thus is not esteemed.
Examples of devices working in the manner mentioned are found in the literature in great numbers. For example, DE-A-4343065 discloses operation with a piston, and U.S. Pat. No. 4,636,164 is equipped with a double row of calender rolls, as well as EP-A-0069078 in which calendering and pressing can be considered essentially equivalent under the aspect of the scope of the present invention as both processes are based on the application of forces pressing perpendicularly relative to the dough to be expanded, Furthermore, WO-96/28979 discloses expansion of the disk of dough from the inner area towards the outer area with the help of a complicated system of pressing segments arranged concentrically which successively are pressed, beginning with the innermost segments nearest to the center and finally the outermost segments are pressed in such a manner that the expansion of the dough is performed by compression from the inner area towards the outermost area. In addition to the great complexity of the design of this device, this system also presents the inherent disadvantages of the compression systems mentioned above.
According to the second category of proposals which are less numerous and which start out from the manual processing system, it is tried to effect the radial expansion of the dough under application of centrifugal force, i.e. by rotating the dough about a rotational axis extending at right angles relative to the disk of dough. These systems thus try to imitate the performance of the pizzaiolo (pizza baker) and indeed the results obtained in this manner are satisfactory as the small bubbles present in the dough before it is expanded into a soft disk remain present and lend the dough the desired degree of softness.
A proposal in this direction is described in U.S. Pat. No. 3,390,645, taken up and improved by the same applicant in U.S. Pat. No. 4,690,043. According to this proposal, the dough is rotated within a room limited radially by a system of tapes held by an arrangement of levers which can perform radial movements. The concept applied here for expanding the pizza dough into a soft disk using the influence of the centrifugal force certainly is correct even if the complexity of the device laid out for this purpose is apt to give room to serious doubts concerning its ease of operation and its operating cost as well as its maintenance cost.